“We are closer to passing this reform than ever before,” said President Obama, after the announcements. “And now that the doctors and medical professionals of America are standing with us; now that the organizations charged with looking out for the interests of seniors are standing with us, we are even closer.”

The AARP board of directors committed the clout of its nearly 40 million-member lobby to the 11th hour fight, including an ad campaign and mobilization of some 5 million activists.

“Beginning today, we will energize all of our resources for passage of the House plan,” said AARP board chair Bonnie Cramer at a mid-day Washington press briefing.

But support of the American Medical Association, announced minutes later, came with a price: that the House also commit to passing a 10-year “fix” to roll back mandated cuts in payments to physicians who serve Medicare patients.

“A successful foundation for health system reform is dependent on House passage of both bills,” said AMA CEO Michael Maves in a letter to House Speaker Nancy Pelosi (D) of California, released today. The Speaker’s office confirms that the House will vote by Thanksgiving on a permanent “fix” to the cost-saving growth formula first proposed in 1997.

In a move the troubles fiscally conservative Democrats, the cost of the bill – estimated to be $210 billion over 10 years – is not expected to be offset, a violation of House "pay-go" rules that require all new spending to be fully funded.

But the most decisive number in a tight race for 218 votes could be 2 – the two Democrats elected to the House on Nov. 3. Rep. John Garamendi (D) of California was sworn in today. Democrat Bill Owens, who won a former GOP seat in upstate New York, is expected to be sworn in on Friday. Both campaigned on support for healthcare reform. These two new Democrats expand the Democrats' majority, which will now stand at 258 to 177.

With as many as 40 Democrats calling for a ban on all federal funding for abortion in the bill, Speaker Pelosi will need those two votes to hit the 218 votes needed for passage. (In short: 258 minus 40 equals 218.) In a bid to improve that math, the House Rules Committee tomorrow is expected to include compromise language that assigns contractors to ensure that abortion services are paid for by private premiums, not public subsidies.

“The bottom line is we’re going to exhaust every avenue to ensure pro-life concerns are addressed in this legislation,” said Rep. Brad Ellsworth (D) of Indiana, who proposed the alternative language on abortion.

On Wednesday, Rep. Bart Stupak (D) of Michigan reaffirmed his opposition to the bill. He and others are expected to meet with President Obama on Friday, when he comes to Capitol Hill for discussions with Democrats on the final vote.

“It is something that many of us have worked our whole political lifetimes on,” said Pelosi, commenting on the healthcare vote in a press conference Thursday.

“It is something that means a great deal to the American people,” she said. “We are thrilled that [the president] is coming tomorrow, and we can have our conversation before we go into the process of bringing this legislation to the floor.”